pre-cruise covid testing in Madrid or Barcelona?

There are many places around both cities that do COVID testing, but it seems that perhaps your cruise line would recommend places?

We had to test in both cities, first to get on the Rick Steves tour, then to fly home. But the places we tested were close to the old , historic centers, not close to cruise ports. If you contact either the cruise line, or the hotel where you will be staying, you should get more relevant information. Both hotels we stayed at had local laboratories they sent guests to.